title: The depressive effects of 5,8,11-eicosatrienoic Acid (20:3n-9) on osteoblasts.
abstract: In cases of essential fatty acid deficiency, 5,8,11-eicosatrienoic acid (Mead acid, 20:3n-9) is synthesized from oleic acid as a 20-carbon analog of arachidonic acid. It was reported that 20:3n-9 levels were markedly higher in human fetal cartilage than in the muscle, liver and spleen. We, therefore, hypothesized that 20:3n-9 decreased osteoblastic activity. Goldfish scales were incubated either with 20:3n-9 or with oleic acid at 15 degrees C for 6 and 18 h. Both osteoblastic and osteoclastic activities in the scale were assessed by measuring alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase, respectively. MC3T3-E1 cells (an osteoblast cell line derived from the mouse) were incubated with 20:3n-9 or oleic acid at 37 degrees C for 6 and 18 h. ALP activity in cell lysate was measured. In the case of experiments with scales, 20:3n-9 (1-100 muM) significantly suppressed osteoblastic activity after 6 and 18 h of incubation, whereas oleic acid did not change this activity. Osteoclastic activity was not affected either by 20:3n-9 or by oleic acid. In the case with the cell line, osteoblastic activity was again significantly decreased with 20:3n-9 (10-30 muM) after 6-h incubation but not after 18 h incubation. The presence of 20:3n-9 in fetal cartilage may be important for the prevention of calcification in the cartilage. 20:3n-9 could be applied to some clinical situations where bone formation should be inhibited.
authors.affiliation: Department of Clinical Sciences, Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama, Toyama 9300194, Japan. hamazaki@inm.u-toyama.ac.jp
authors.forename: Tomohito
authors.initials: T
authors.lastname: Hamazaki
authors.forename: Nobuo
authors.initials: N
authors.lastname: Suzuki
authors.forename: Retno
authors.initials: R
authors.lastname: Widyowati
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Miyahara
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Kadota
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ochiai
authors.forename: Kei
authors.initials: K
authors.lastname: Hamazaki
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D000135:Acid Phosphatase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D003864:Depression, Chemical; D005260:Female; D006054:Goldfish; D007527:Isoenzymes / Q000378:metabolism; D051379:Mice; D019301:Oleic Acid / Q000494:pharmacology; D010006:Osteoblasts / Q000187:drug effects* / Q000502:physiology; D010010:Osteoclasts / Q000187:drug effects / Q000502:physiology; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D007527:Isoenzymes; D019301:Oleic Acid; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D015126:8,11,14-Eicosatrienoic Acid; C010944:mead acid